Earlier quoted context omitted.
The older “608”[1] system in North America was much simpler but the current “708”[2] standard does support specifying colours and fonts, but in my experience in the industry nobody uses those functions at all and just uses the 708 function to embed the older 608 payload data within the newer 708 data structure. In UK/Europe the older/simpler format would be OP-42/OP-47 Teletext[3] which can be used for captions inste…
Yeah, I know of the "708" captioning system but it is surprisingly underutilized* by broadcasters. I think that they don't see any use for e.g. color? * in terms of 708-only features, not on the pedantic "ATSC uses the 708 system"
The requirements are quite high in Canada[1] and have been expanding in the US as well[2].
The company I work for makes products for broadcast customers, around asset management, linear playout automation, and the playout servers that insert the captions (from files or live data sources) so working out how that all happens is part of every big project.
[1] https://crtc.gc.ca/eng/info_sht/b321.htm [2] https://www.fcc.gov/consumers/guides/closed-captioning-telev...